1. Field of the Invention
The present invention relates to a tailgate lift assembly and particularly to a device which allows a tailgate which is hingedly attached to a trailer to be raised and lowered with relative ease due to the biasing of the lift assembly.
2. Description of the Prior Art
Prior art tailgate lift assemblies which are being utilized in combination with a trailer and tailgate typically use hydraulics or other cantilevered pivot arms in order to aid in the raising and lowering of the tailgate. These prior art tailgate lift assembly devices further traditionally require integration into the side wall or bed of the trailer in order to adequately provide biasing of the tailgate in the upward or downward direction. Such biasing allows the tailgate to be raised and lowered with relative ease.
However, the integration of the biasing devices into the side-rail or bed of the trailer proves to be difficult in the manufacturing of the trailer device or in modifying of the trailer device due to the structure of the pivoting arms or the inclusion of the hydraulic support cylinders.
Further devices have provided a mechanism for lifting tailgates wherein cables may be utilized, but which must necessarily be positioned such that interference in the truck bed is required. U.S. Pat. No. 4,601,485 discloses such a mechanism wherein a cable interferes with a trailer hitching device for a fifth wheel vehicle in order to actuate raising and lowering of the tailgate.
Other mechanisms are known which combine spring type devices and hydraulic means for raising and lowering gates from a vertical and horizontal position. U.S. Pat. No. 3,303,613 discloses utilization of multiple spring devices in addition to hydraulic cylinders in order to provide biasing means for raising and lowering of the gate. However, utilization of the above-listed devices proves to be unusable in combination with a trailer due to proper positioning of the material elements and the inability of integrating these elements with a standard trailer bed and side rail.
These and other devices of the prior art fail to be easily integrated with presently existing trailers and require extensive engineering and manufacturing at the time of assembly of the trailer.
In the prior art, there does not exist a simplified unit for providing a tailgate lift assembly which works in combination with the trailer and the tailgate such that the lift assembly is integrated with the trailer side-rail, which provides adequate biasing of the tailgate for relative ease of raising and lowering the tailgate and which may be readily integrated with existing trailer side-rails.